Trapped in the Supply Closet

You are working late on Friday to get your classroom ready for your students first thing Monday morning. You go down to the basement supply room to get some bulletin board paper. When you walk over to the paper, the door closes and locks behind you. To make matters worse, you don’t have your phone.

Luckily in the corner you see a box labeled “Master Keys”. The box has four locks on it. If you can unlock all the locks, you will have the master key and will get out of the room without waiting for someone to find you.